Comment 63 for bug 1446865

(In reply to Sergio from comment #60)
> KDE web page that KDE development mainly focuses on single user workflows
Session restorage has nothing to do with single/multiuser questions.
It's about session restarts, not about multiple sessions.

> - if wily's qt 5.4.2 contains the same fixes that are in the Fedora package
> mentioned above and if it can be safely backported to vivid in a ppa
See comment #49 and comment #52 on the Qt patches.
They're not in Qt upstream - not even reviewed.

> what additional patches are needed on top of the kwin package contained in the kubuntu kde
> backports ppa, to see if a fixed package can be shipped in a further PPA
I don't know what's in "backports ppa", but you'll need either KWin >= 5.4.0 (not yet released) or https://git.reviewboard.kde.org/r/123580/ + the forementioned Qt patches (for Qt5/KF5 clients - otherwise only Qt4/gtk/etc clients are properly restored by kwin)

For client internal issues (what especially also includes "restarting Qt5 applications" when "restoring the last session" itfp) I'm not aware of any present patches.